The National Zoo conducted their second exam on the as-yet unnamed panda cub yesterday, confirming not only that the baby is indeed a boy (not evident from the picture — that’s its tail, silly) but that panda moms love their babies. Hearing the little guy squeal made Mei Xiang become agitated and run around the enclosure. She defecated and also vocalized, producing sharp high-pitched barks. After was reunited with her cub and had the cub…